Ciphertext

Ciphertext is information that has been encrypted, meaning a cipher and a key have turned readable data, or plaintext, into a form that looks like random characters. Only someone with the correct key can decrypt it back to the original. Good ciphertext reveals nothing useful about its content, apart from roughly how long it is. Banks, payment processors and messaging apps store and transmit sensitive data such as card numbers, passwords and messages as ciphertext, so that intercepted data is useless to an attacker; end-to-end encryption keeps it as ciphertext throughout its journey. Ciphertext is different from a hash, which cannot be reversed with any key, as described under Cryptographic Hash Function. Also see Digital Encryption and Decryption.